Research And Development Of Test System For X-ray Dectection And Front-end Processing Modules

As a key technology that ICT Research Center of Chongqing University has researched and developed independently, X-ray detection and front-end processing modules are core components of industrial X-CT system. Some parts of the modules are commissioned to produce by foreign companies. As the demand of industrial CT increased, the demand of X-ray detection and front-end processing modules has also increased. Sometimes the imported modules and the actual needs of ICT system are inconsistent. Therefore it is necessary to test the performance of each module to ensure they can meet the requirements of CT system.For this demand, this subject has developed a test system capable of testing the above-mentioned modules. The system can transmit test data to host computer to save and display for analysis by users, therefore it can play a role of real-time monitoring and tracking production process of the modules. The test system mainly includes two parts: data acquisition and transmission module and PC user test software. According to function and performance requirements of the two parts, hardware and software projects are determined firstly in this paper, and then the design of these two parts are described in details and the system is tested in the end.In the hardware design, a data acquisition and transmission test board which is based on FPGA and USB2.0 technology is designed. The functions that FPGA can collect data parallel and USB2.0 can transfer data in high speed and real time are used. The FPGA chip is Cyclone EP1C6T144C8N of Altera Corporation and USB chip is EZ-USB FX2 CY7C68013A of Cypress Corporation. In the process of data acquisition and transmission, FPGA is the main controller and USB2.0 works in slave FIFO mode. Firstly, FPGA controls analog-to-digital converter to convert analog singal transferred from dectection module to digital, and then it sends the data which have been converted to the endpoint buffer of USB. At last, the USB chip transmits the data to host computer.In the software design, FPGA digital logic, USB firmware, USB driver and host computer application are designed. In FPGA logic design, we use top-down method and programm by Verilog HDL language in Quartus II software platform. The development of USB firmware and driver is programmed based on program framework that Cypress Corporation provides. Host computer application is programmed in VC6.0, using multi-threaded technology to create interface thread and data reception thread. It interacts with USB driver through I/O control code of WIN32API function.In view of acquisition and transmission speed, stability and reliability, the system is tested many times and debugged with dectetion and front-end electronic modules in the end. The test results show that the system is well designed and it can achieve expected effects. It also has a certain guiding role of other data acquisition and transmission test system.